Tub defining integral rack guides in a dishwasher appliance

ABSTRACT

A dishwasher appliance includes a tub defining a wash chamber for receipt of articles for washing and a guide assembly defined by the tub and including an upper guide and a lower guide spaced apart along the vertical direction to define a support groove having a retention geometry proximate a front opening of the tub. A rack is positioned within the support groove and is slidable along the transverse direction between a retracted position and an extended position, the rack defining a rear retention member that engages the upper guide at the retention geometry when the rack reaches the extended position.

FIELD OF THE INVENTION

The present disclosure relates generally to dishwasher appliances, and more particularly to improved, low-cost rack assemblies and mounting methods for dishwasher appliances.

BACKGROUND OF THE INVENTION

Dishwasher appliances generally include a tub that defines a wash chamber. Rack assemblies can be mounted within the wash chamber of the tub for receipt of articles for washing. Multiple spray assemblies can be positioned within the wash chamber for applying or directing wash fluid towards articles disposed within the rack assemblies in order to clean such articles. Dishwasher appliances are also typically equipped with at least one pump for circulating fluid through the multiple spray assemblies. In addition, devices referred to as diverters may be used to control the flow of fluid received from the pump.

In addition to conventional lower and middle rack assemblies, certain dishwasher appliances include a “third rack” or “upper rack” positioned above the lower and middle rack assemblies, e.g., for receiving flatware, cutlery, or other cooking utensils. Notably, mounting these third racks typically requires a large number of parts, increased costs, and long assembly times. For example, mounting a conventional third rack may require upwards of 30 parts, including screws, tub mount brackets, tub-side rollers, washers, rail systems, rack side roller assemblies, and the rack. In addition to the expenses associated with the parts and assembly, these complex assemblies may be more prone to failure, degradation, and/or increased maintenance costs.

Accordingly, a dishwasher appliance that utilizes improved rack mounting features would be useful. More specifically, a third rack assembly that has fewer parts, requires less time to manufacture and assemble, and provides for a robust rack mounting solution would be particularly beneficial.

BRIEF DESCRIPTION OF THE INVENTION

Aspects and advantages of the invention will be set forth in part in the following description, or may be apparent from the description, or may be learned through practice of the invention.

In one exemplary embodiment, a dishwasher appliance is provided defining a vertical direction, a lateral direction, and a transverse direction. The dishwasher appliance includes a tub defining a guide assembly including an upper guide and a lower guide spaced apart from the upper guide along the vertical direction to define a support groove having a retention geometry proximate a front opening of the tub and a rack positioned within the support groove and being slidable along the transverse direction between a retracted position and an extended position, the rack defining a rear retention member that engages the upper guide at the retention geometry when the rack reaches the extended position.

In another exemplary embodiment, a tub for a dishwasher appliance is provided. The tub includes a first sidewall and a second sidewall spaced apart along a lateral direction and a guide assembly integrally formed on each of the first sidewall and the second sidewall, each guide assembly comprising an upper guide and a lower guide spaced apart from the upper guide along a vertical direction to define a support groove having a retention geometry proximate a front opening of the tub.

These and other features, aspects and advantages of the present invention will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures.

FIG. 1 provides a perspective view of an exemplary embodiment of a dishwashing appliance of the present disclosure with a door in a partially open position.

FIG. 2 provides a side, cross sectional view of the exemplary dishwashing appliance of FIG. 1 .

FIG. 3 provides a perspective view of a third rack assembly of the exemplary dishwashing appliance of FIG. 1 with the rack in a retracted position according to an exemplary embodiment of the present subject matter.

FIG. 4 provides a perspective view of the exemplary third rack assembly of FIG. 3 with the rack in an extended position according to an exemplary embodiment of the present subject matter.

FIG. 5 provides a perspective view of a tub and guide assembly for supporting a third rack according to an example embodiment of the present subject matter.

FIG. 6 provides a front schematic view of the exemplary tub and guide assembly of FIG. 5 according to an example embodiment of the present subject matter.

Repeat use of reference characters in the present specification and drawings is intended to represent the same or analogous features or elements of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Reference now will be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment can be used with another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents.

As used herein, the terms “includes” and “including” are intended to be inclusive in a manner similar to the term “comprising.” Similarly, the term “or” is generally intended to be inclusive (i.e., “A or B” is intended to mean “A or B or both”). Approximating language, as used herein throughout the specification and claims, is applied to modify any quantitative representation that could permissibly vary without resulting in a change in the basic function to which it is related. Accordingly, a value modified by a term or terms, such as “about,” “approximately,” and “substantially,” are not to be limited to the precise value specified. In at least some instances, the approximating language may correspond to the precision of an instrument for measuring the value. For example, the approximating language may refer to being within a 10 percent margin.

As used herein, the term “article” may refer to, but need not be limited to dishes, pots, pans, silverware, and other cooking utensils and items that can be cleaned in a dishwashing appliance. The term “wash cycle” is intended to refer to one or more periods of time during which a dishwashing appliance operates while containing the articles to be washed and uses a detergent and water, preferably with agitation, to e.g., remove soil particles including food and other undesirable elements from the articles. The term “rinse cycle” is intended to refer to one or more periods of time during which the dishwashing appliance operates to remove residual soil, detergents, and other undesirable elements that were retained by the articles after completion of the wash cycle. The term “drain cycle” is intended to refer to one or more periods of time during which the dishwashing appliance operates to discharge soiled water from the dishwashing appliance. The term “wash fluid” refers to a liquid used for washing and/or rinsing the articles and is typically made up of water that may include other additives such as detergent or other treatments.

FIGS. 1 and 2 depict an exemplary domestic dishwasher or dishwashing appliance 100 that may be configured in accordance with aspects of the present disclosure. For the particular embodiment of FIGS. 1 and 2 , the dishwasher 100 includes a cabinet 102 (FIG. 2 ) having a tub 104 therein that defines a wash chamber 106. As shown in FIG. 2 , tub 104 extends between a top 107 and a bottom 108 along a vertical direction V, between a pair of side walls 110 along a lateral direction L, and between a front side 111 and a rear side 112 along a transverse direction T. Each of the vertical direction V, lateral direction L, and transverse direction T are mutually perpendicular to one another.

The tub 104 includes a front opening 114 and a door 116 hinged at its bottom for movement between a normally closed vertical position (shown in FIG. 2 ), wherein the wash chamber 106 is sealed shut for washing operation, and a horizontal open position for loading and unloading of articles from the dishwasher 100. According to exemplary embodiments, dishwasher 100 further includes a door closure mechanism or assembly 118 that is used to lock and unlock door 116 for accessing and sealing wash chamber 106.

As best illustrated in FIG. 2 , tub side walls 110 accommodate a plurality of rack assemblies. More specifically, guide rails 120 may be mounted to side walls 110 for supporting a lower rack assembly 122, a middle rack assembly 124, and a third rack assembly 126. As illustrated, third rack assembly 126 is positioned at a top portion of wash chamber 106 above middle rack assembly 124, which is positioned above lower rack assembly 122 along the vertical direction V. Each rack assembly 122, 124, 126 is adapted for movement between an extended loading position (not shown) in which the rack is substantially positioned outside the wash chamber 106, and a retracted position (shown in FIGS. 1 and 2 ) in which the rack is located inside the wash chamber 106. This is facilitated, for example, by rollers 128 mounted onto rack assemblies 122, 124, 126, respectively. Although a guide rails 120 and rollers 128 are illustrated herein as facilitating movement of the respective rack assemblies 122, 124, 126, it should be appreciated that any suitable sliding mechanism or member may be used according to alternative embodiments.

Some or all of the rack assemblies 122, 124, 126 are fabricated into lattice structures including a plurality of wires or elongated members 130 (for clarity of illustration, not all elongated members making up rack assemblies 122, 124, 126 are shown in FIG. 2 ). In this regard, rack assemblies 122, 124, 126 are generally configured for supporting articles within wash chamber 106 while allowing a flow of wash fluid to reach and impinge on those articles, e.g., during a cleaning or rinsing cycle. According to another exemplary embodiment, a silverware basket (not shown) may be removably attached to a rack assembly, e.g., lower rack assembly 122, for placement of silverware, utensils, and the like, that are otherwise too small to be accommodated by rack 122.

Dishwasher 100 further includes a plurality of spray assemblies for urging a flow of water or wash fluid onto the articles placed within wash chamber 106. More specifically, as illustrated in FIG. 2 , dishwasher 100 includes a lower spray arm assembly 134 disposed in a lower region 136 of wash chamber 106 and above a sump 138 so as to rotate in relatively close proximity to lower rack assembly 122. Similarly, a mid-level spray arm assembly 140 is located in an upper region of wash chamber 106 and may be located below and in close proximity to middle rack assembly 124. In this regard, mid-level spray arm assembly 140 may generally be configured for urging a flow of wash fluid up through middle rack assembly 124 and third rack assembly 126. Additionally, an upper spray assembly 142 may be located above third rack assembly 126 along the vertical direction V. In this manner, upper spray assembly 142 may be configured for urging and/or cascading a flow of wash fluid downward over rack assemblies 122, 124, and 126.

The various spray assemblies and manifolds described herein may be part of a fluid distribution system or fluid circulation assembly 150 for circulating water and wash fluid in the tub 104. More specifically, fluid circulation assembly 150 includes a pump 152 for circulating water and wash fluid (e.g., detergent, water, and/or rinse aid) in the tub 104. Pump 152 may be located within sump 138 or within a machinery compartment located below sump 138 of tub 104, as generally recognized in the art. Fluid circulation assembly 150 may include one or more fluid conduits or circulation piping for directing water and/or wash fluid from pump 152 to the various spray assemblies and manifolds. For example, as illustrated in FIG. 2 , a primary supply conduit 154 may extend from pump 152, along rear 112 of tub 104 along the vertical direction V to supply wash fluid throughout wash chamber 106.

As illustrated, primary supply conduit 154 is used to supply wash fluid to one or more spray assemblies, e.g., to mid-level spray arm assembly 140 and upper spray assembly 142. However, it should be appreciated that according to alternative embodiments, any other suitable plumbing configuration may be used to supply wash fluid throughout the various spray manifolds and assemblies described herein. For example, according to another exemplary embodiment, primary supply conduit 154 could be used to provide wash fluid to mid-level spray arm assembly 140 and a dedicated secondary supply conduit (not shown) could be utilized to provide wash fluid to upper spray assembly 142. Other plumbing configurations may be used for providing wash fluid to the various spray devices and manifolds at any location within dishwasher appliance 100.

Each spray arm assembly 134, 140, 142 or other spray device may include an arrangement of discharge ports or orifices for directing wash fluid received from pump 152 onto dishes or other articles located in wash chamber 106. The arrangement of the discharge ports, also referred to as jets, apertures, or orifices, may provide a rotational force by virtue of wash fluid flowing through the discharge ports. Alternatively, spray arm assemblies 134, 140, 142 may be motor-driven, or may operate using any other suitable drive mechanism. Spray manifolds and assemblies may also be stationary. The resultant movement of the spray arm assemblies 134, 140, 142 and the spray from fixed manifolds provides coverage of dishes and other dishwasher contents with a washing spray. Other configurations of spray assemblies may be used as well. For example, dishwasher 100 may have additional spray assemblies for cleaning silverware, for scouring casserole dishes, for spraying pots and pans, for cleaning bottles, etc. One skilled in the art will appreciate that the embodiments discussed herein are used for the purpose of explanation only, and are not limitations of the present subject matter.

In operation, pump 152 draws wash fluid in from sump 138 and pumps it to a diverter assembly 156, e.g., which is positioned within sump 138 of dishwasher appliance. Diverter assembly 156 may include a diverter disk (not shown) disposed within a diverter chamber 158 for selectively distributing the wash fluid to the spray arm assemblies 134, 140, 142 and/or other spray manifolds or devices. For example, the diverter disk may have a plurality of apertures that are configured to align with one or more outlet ports (not shown) at the top of diverter chamber 158. In this manner, the diverter disk may be selectively rotated to provide wash fluid to the desired spray device.

According to an exemplary embodiment, diverter assembly 156 is configured for selectively distributing the flow of wash fluid from pump 152 to various fluid supply conduits, only some of which are illustrated in FIG. 2 for clarity. More specifically, diverter assembly 156 may include four outlet ports (not shown) for supplying wash fluid to a first conduit for rotating lower spray arm assembly 134 in the clockwise direction, a second conduit for rotating lower spray arm assembly 134 in the counter-clockwise direction, a third conduit for spraying an auxiliary rack such as the silverware rack, and a fourth conduit for supply mid-level and/or upper spray assemblies 140, 142, i.e., such as primary supply conduit 154.

The dishwasher 100 is further equipped with a controller 160 to regulate operation of the dishwasher 100. The controller 160 may include one or more memory devices and one or more microprocessors, such as general or special purpose microprocessors operable to execute programming instructions or micro-control code associated with a cleaning cycle. The memory may represent random access memory such as DRAM, or read only memory such as ROM or FLASH. In one embodiment, the processor executes programming instructions stored in memory. The memory may be a separate component from the processor or may be included onboard within the processor. Alternatively, controller 160 may be constructed without using a microprocessor, e.g., using a combination of discrete analog and/or digital logic circuitry (such as switches, amplifiers, integrators, comparators, flip-flops, AND gates, and the like) to perform control functionality instead of relying upon software.

The controller 160 may be positioned in a variety of locations throughout dishwasher 100. In the illustrated embodiment, the controller 160 may be located within a control panel area 162 of door 116 as shown in FIGS. 1 and 2 . In such an embodiment, input/output (“I/O”) signals may be routed between the control system and various operational components of dishwasher 100 along wiring harnesses that may be routed through the bottom of door 116. Typically, the controller 160 includes a user interface panel/controls 164 through which a user may select various operational features and modes and monitor progress of the dishwasher 100. In one embodiment, the user interface 164 may represent a general purpose I/O (“GPIO”) device or functional block. In one embodiment, the user interface 164 may include input components, such as one or more of a variety of electrical, mechanical or electro-mechanical input devices including rotary dials, push buttons, and touch pads. The user interface 164 may include a display component, such as a digital or analog display device designed to provide operational feedback to a user. The user interface 164 may be in communication with the controller 160 via one or more signal lines or shared communication busses.

It should be appreciated that the invention is not limited to any particular style, model, or configuration of dishwasher 100. The exemplary embodiment depicted in FIGS. 1 and 2 is for illustrative purposes only. For example, different locations may be provided for user interface 164, different configurations may be provided for rack assemblies 122, 124, 126, different spray arm assemblies 134, 140, 142 and spray manifold configurations may be used, and other differences may be applied while remaining within the scope of the present subject matter.

Referring now generally to FIGS. 2 through 6 , a third rack assembly and a guide assembly 200 that may be used with dishwasher 100 will be described in more detail according to an exemplary embodiment of the present subject matter. As best shown in FIGS. 3 and 4 , dishwasher 100 includes guide assembly 200 for mounting a third rack 202 (e.g., such as third rack assembly 126) to tub 104. According to the illustrated embodiment, dishwasher appliance 100 includes two guide assemblies 200 defined on opposite lateral sides of tub 104 within wash chamber 106 for supporting third rack 202. Specifically, according to exemplary embodiments of the present subject matter, the two guide assemblies 200 may be integrally formed with tub 104 and may be mirror images of each other. However, it should be appreciated that variations may be made to tub 104 and guide assemblies 200 while remaining within the scope of the present subject matter.

Exemplary guide assemblies 200 and third rack 202 are described herein to facilitate discussion of aspects of the present subject matter. However, it should be appreciated that the present subject matter is not limited to the specific embodiments described. For example, variations in guide assembly 200 may be made for supporting other dishwasher racks while remaining within the scope of the present subject matter. In this regard, although guide assembly 200 is described herein as supporting an upper, third rack 202, it should be appreciated that according to alternative embodiments, guide assembly 200 may support any other dishwasher racks within any suitable dishwasher, such as the rack of lower rack assembly 122, the rack of middle rack assembly 124, etc. Other variations are possible and within the scope of the present subject matter.

As best illustrated in FIG. 6 , dishwasher appliance 100 includes two guide assemblies 200 for supporting each rack 202. In this regard, guide assemblies 200 may be mirror images of each other and may be positioned at the same vertical position in order to support third rack 202 in a horizontal orientation. Although only two guide assemblies 200 are illustrated herein for supporting a single third rack 202, it should be appreciated that additional guide assemblies 200 may be positioned along the height of side walls 110 for supporting other racks at other suitable heights. In addition, it should be appreciated that third rack 202 may be interchangeable with each of these additional sets of guide assemblies 200, such that a user may selectively position third rack 202 at any suitable height within wash chamber 106.

Notably, according to the illustrated embodiment, third rack 202 is positioned at the very top of wash chamber 106, e.g., proximate a top wall 107. Accordingly, guide assemblies 200 are generally positioned at the top corners of tub 104. More specifically, tub 104 defines arcuate corners 204 where top wall 107 and the left and right side walls 110 meet. Arcuate corners 204 may be used in tub 104 of dishwasher appliance 100 to simplify the formation process and improve the structural rigidity of tub 104. According to exemplary embodiments of the present subject matter, tub 104 is formed from stainless steel or any other suitably rigid material. According to still other embodiments, tub 104 may be injection-molded using any suitable plastic material, as described more detail below.

In general, the exemplary embodiments of tub 104 and guide assembly 200 described herein may be manufactured or formed using any suitable process. However, in accordance with several aspects of the present subject matter, tub 104 and guide assembly 200 are formed through any suitable manufacturing process that allows tub 104 and guide assembly 200 to be formed integrally, as a single monolithic component. For example, according to exemplary embodiments, guide assembly 200 may be formed directly into tub 104 by injection molding using any suitable plastic or polymer material. In this regard, guide assembly 200 and tub 104 may be formed by injection molding, e.g., using a suitable plastic material, such as injection molding grade high impact polystyrene (HIPS) or acrylonitrile butadiene styrene (ABS). Alternatively, according to the exemplary embodiment, these components may be compression molded, e.g., using sheet molding compound (SMC) thermoset plastic or other thermoplastics. According to still other embodiments, tub 104 and guide assembly 200 may be formed from metal or any other suitable rigid material, such as sheet metal. In this regard, guide assembly 200 may be formed directly into tub 104 by a stamping or metal forming process. According to alternative embodiments, tub 104 and guide assembly 200 may be formed using any suitable manufacturing process and any suitable material that is sufficiently rigid to support internal components of dishwasher 100 during appliance operation.

Notably, this formation process where guide assembly 200 is integrally formed into tub 104 provides several advantages. For example, as noted above, conventional rack mounting assemblies require many parts, necessitate a long and complex assembly process, and are very expensive. By contrast, the present construction provides a rigid tub with rack mounting features integrated therein as a single, integral, and monolithic part. This construction reduces part costs, assembly time, and maintenance costs. Other advantages of such a construction will be apparent to those having ordinary skill in the art.

Third rack 202 may generally be formed from any suitable materials and may have any suitable construction or configuration. For example, according to the illustrated embodiment, third rack 202 comprises two lateral support wires 210 (e.g., which engage guide assemblies 200). In addition, the primary support surface of third rack 202 (e.g., for supporting utensils or articles to be cleaned) is plurality of interwoven interior wires 212 that extends between and connects the lateral support wires 210. As best shown in FIGS. 3 and 4 , lateral support wires 210 may generally have a larger diameter than the plurality of interwoven interior wires 212, e.g., to support structural loading of third rack 202.

Both lateral support wires 210 and interwoven interior wires 212 may be formed from any suitable material or materials that may result in a suitably rigid third rack 202 while minimizing costs and weight. Thus, according to exemplary embodiments, these wires may be formed from a suitably rigid metal material and may be coated in nylon. According to still other embodiments, these wires may be formed from stainless steel (e.g., which may require no coating at all). Notably, conventional third racks 202 are formed from plastic and thus insulate utensils placed thereon, resulting in slower drying times. However, forming these support wires from metal as described herein may improve the drying performance of dishwasher 100.

Referring still generally to FIGS. 3 through 6 , guide assemblies 200 will be described in more detail according to exemplary embodiments of the present subject matter. Specifically, as illustrated, each guide assembly 200 includes an upper guide 220 and a lower guide 222 that are spaced apart from each other along the vertical direction V to define a support groove 224 there between. In this regard, support groove 224 is generally sized for slidably receiving lateral support wires 210 of third rack 202. In this manner, third rack 202 may generally slide along the transverse direction T between a retracted position (e.g., as shown in FIG. 3 ) and an extended position (e.g., as shown in FIG. 4 ).

As best shown in FIGS. 3 through 6 , guide assembly 200 may generally be positioned within arcuate corner 204 of tub 104. In this manner, guide assembly 200 may add additional mass to arcuate corner 204, e.g., to improve the structural rigidity of tub 104. In addition, positioning guide assembly 200 in the top corner of tub 104 provides for a low-profile third rack 202 that takes up little space and does not conflict with lower rack assemblies. As illustrated, guide assembly 200 may further include a standoff 226 that is positioned in arcuate corner 204 and that defines a vertical face 228. As shown, upper guide 220 and lower guide 222 extend from the vertical face 228 substantially along the lateral direction L. In this manner, standoff 226 helps transition from the curved arcuate corner to a planar vertical face 228 suitable for improving the sliding motion of third rack 202. Although the illustrated embodiment shows guide assembly 200 being positioned within arcuate corner 204, it should be appreciated that guide assembly 200 may be positioned at other suitable locations (e.g., such as on side walls 110) while remaining within the scope of the present subject matter.

Notably, it may be desirable to prevent a user from pulling third rack 202 completely out of guide assembly 200, e.g., to prevent third rack 202 and all its contents from spilling onto the floor. As a result, upper guide 220 and lower guide 222 may be shaped to define a retention geometry 230 proximate front opening 114 of tub 104, e.g., proximate a front end 232 of guide assembly 200. Similarly, guide assembly 200 may define a rear stop 234 proximate a rear end 236 of guide assembly 200 (e.g., proximate rear 112 of tub 104). Notably, retention geometry 230 and rear stop 234 are generally configured for engaging third rack 202 at the desired locations to prevent further movement along the transverse direction T. Each of these features will be described in detail below.

In addition, third rack 202 may define features for preventing undesirable removal of third rack 202 from guide assembly 200. Specifically, according to the illustrated embodiment, third rack 202 may define a rear retention member 240 that is generally configured for engaging guide assembly 200 when lower rack 202 is in the extended position to prevent further extension of third rack 202. Specifically, according to the illustrated embodiment, retention geometry 230 may include a downward protrusion 242 defined in both upper guide 220 and lower guide 222. In addition, rear retention member 240 may extend upward from lateral support wires 210 along the vertical direction V. As such, rear retention member 240 may contact or engage downward protrusion when lower rack 202 reaches the extended position, such that further removal of third rack 202 is prevented. It should be appreciated that the size, position, and geometry of rear retention member 240 and retention geometry 230 may vary while remaining within the scope of the present subject matter.

Notably, retention geometry 230 and rear retention member 240 may be configured for preventing movement of third rack 202 directly along the transverse direction T after it reaches the extended position. However, if a user wishes to remove third rack 202, the user may pivot a front end of third rack 202 upward along the vertical direction V when third rack 202 is in the extended position and may thereby guide rear retention member 240 of around downward protrusion 242 to permit rack removal. It should be appreciated that other stopping mechanisms for preventing removal of third rack 202 are possible and within scope the present subject matter.

As best shown in FIGS. 3 and 5 , rear stop 234 may include a tapered extension 250 of upper guide 220 that decreases a height 252 of support groove 224 as measured along the vertical direction V. In this regard, height 252 of support groove 224 is generally constant along the entire guide assembly 200. However, tapered extension 250 may decrease height 252 proximate rear end 236 such that the constriction engages rear retention member 240 to prevent further movement of third rack 202 past the retracted position.

As best shown in FIG. 6 , the integral formation of guide assembly 200 within tub 104 may generally facilitate the use of wider third racks 202, thereby increasing the total wash capacity of dishwasher appliance 100. Specifically, by integrally forming upper guide 220 and lower guide 222, the overall width of guide assembly 200 may be minimized such that the overall width of third rack 202 may be maximized. In this regard, for example, tub 104 may generally define an interior tub width 260 measured along the lateral direction L and third rack 202 may define a rack width 262 measured along the lateral direction L. According to exemplary embodiments of the present subject matter, rack width 262 may be greater and 75%, greater than 80%, greater than 85%, greater than 90%, greater than 95%, greater than 98%, or greater, of tub width 260.

This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims. 

1. A dishwasher appliance defining a vertical direction, a lateral direction, and a transverse direction, the dishwasher appliance comprising: a tub defining a guide assembly comprising an upper guide and a lower guide spaced apart from the upper guide along the vertical direction to define a support groove having a retention geometry proximate a front opening of the tub, wherein the retention geometry comprises a downward protrusion defined in both of the upper guide and the lower guide; and a rack positioned within the support groove and being slidable along the transverse direction between a retracted position and an extended position, the rack defining a rear retention member that engages the upper guide at the retention geometry when the rack reaches the extended position, and wherein the rack defines two lateral support wires, each of the lateral support wires defining an upward protrusion proximate a front of the lateral support wires for engaging the downward protrusion defined on the upper guide when the rack is in the retracted position.
 2. The dishwasher appliance of claim 1, wherein the tub defines a sidewall and a top wall joined by an arcuate corner, and wherein the upper guide and the lower guide are defined at least partially within the arcuate corner.
 3. The dishwasher appliance of claim 2, wherein the tub further defines a standoff that is positioned in the arcuate corner and defines a vertical face, wherein the upper guide and the lower guide extend from the vertical face along the lateral direction.
 4. The dishwasher appliance of claim 2, wherein the upper guide and the lower guide are formed on the sidewall of the tub.
 5. The dishwasher appliance of claim 1, wherein the support groove is configured to receive at least one of a lower rack, a middle rack, or a third rack.
 6. The dishwasher appliance of claim 1, wherein the tub comprises two sidewalls spaced apart along the lateral direction, and wherein each of the two sidewalls defines at least two pairs of guide assemblies at different positions along the vertical direction for supporting separate dishwasher racks.
 7. The dishwasher appliance of claim 1, wherein the guide assembly comprises a rear stop proximate a rear end of the tub for engaging the rear retention member to prevent sliding the rack past the retracted position.
 8. The dishwasher appliance of claim 7, wherein the rear stop comprises a tapered extension of the upper guide that decreases a height of the support groove.
 9. (canceled)
 10. The dishwasher appliance of claim 1, wherein the rack is removable from the support groove by pivoting a front end of the rack upward when in the extended position and guiding the rear retention member around the downward protrusion.
 11. The dishwasher appliance of claim 1, wherein the rack comprises a plurality of wires that are formed from metal and coated in nylon.
 12. The dishwasher appliance of claim 1, wherein the tub and the guide assembly are integrally formed as a single monolithic component.
 13. The dishwasher appliance of claim 12, wherein the tub and the guide assembly are injection molded as a single piece.
 14. The dishwasher appliance of claim 12, wherein the tub and the guide assembly are stamped from a single piece of stainless steel.
 15. The dishwasher appliance of claim 1, wherein the two lateral support wires are connected by a plurality of interwoven interior wires, wherein the lateral support wires have a larger diameter than the plurality of interwoven interior wires.
 16. The dishwasher appliance of claim 1, wherein the tub defines a tub width measured along the lateral direction and the rack defines a rack width measured along the lateral direction, and wherein the rack width is greater than 90% of the tub width.
 17. The dishwasher appliance of claim 16, wherein the rack width is greater than 95% of the tub width.
 18. A tub for a dishwasher appliance, the tub comprising: a first sidewall and a second sidewall spaced apart along a lateral direction; and a guide assembly integrally formed on each of the first sidewall and the second sidewall, each guide assembly comprising an upper guide and a lower guide spaced apart from the upper guide along a vertical direction to define a support groove having a retention geometry proximate a front opening of the tub, wherein the retention geometry comprises a downward protrusion defined in both of the upper guide and the lower guide, the downward protrusion being configured to engage an upward protrusion defined on a front of lateral support wires of a dishwasher rack.
 19. The tub of claim 18, further comprising: a top wall that is joined to each of the first sidewall and the second sidewall by an arcuate corner, and wherein the upper guide and the lower guide of each of the first sidewall and the second sidewall are defined at least partially within the arcuate corner.
 20. The tub of claim 19, further comprising: a standoff defined within the arcuate corner and defining a vertical face, wherein the upper guide and the lower guide extend from the vertical face along the lateral direction.
 21. The dishwasher appliance of claim 1, further comprising: a plurality of protrusions defined on a top surface of the lower guide and extending upward along the vertical direction to engage the lateral support wires. 